This study aimed to train and validate deep learning systems (DLS) to differentiate between microvascular ischemic ocular motor nerve palsy (v-OMNP) and inflammatory ocular motor nerve palsy (i-OMNP). The method involves using clearly diagnosed v-OMNP and i-OMNP patients from the Department of Neurology database at Beijing Tongren Hospital for further DLS validation, aiding in the differential diagnosis of the aforementioned diseases.

The diagnosis of disease is the outcome of the study. The inclusion criteria and exclusion criteria were as follows:

1. Inclusion Criteria:

   • Patients with acute bilateral diplopia within 1 week of onset at admission.

     1. Ischemic Group:

     1. Sudden onset of unilateral CN III, CN IV, or CN VI palsy.
     2. Isolated CN III (without pupil involvement), CN IV, or CN VI palsy.
     3. Presence of vascular risk factors (VRFs).
     4. Significant symptom recovery no earlier than 2 months after onset, with complete (or nearly complete) recovery within 3-6 months.

     2. Inflammatory Group:

     1. Unilateral painful CN III, CN IV, and/or CN VI palsy.
     2. Symptoms (including pain or diplopia signs) significantly improved within 72 hours after treatment with corticosteroids.
     3. MRI of the cavernous sinus showing inflammation, i.e., abnormal widening/enhancement of the affected cavernous sinus with or without granulomatous changes/inflammatory manifestations of adjacent tissues.

2. Exclusion Criteria:

   • 1. Ocular muscle palsy confirmed to be caused by tumors, trauma, infections, stroke, carotid-cavernous fistula, aneurysms, neuromuscular junction disorders, thyroid-related eye diseases, and hereditary diseases at onset or during follow-up.

     2. Presence of other neurological signs in addition to ocular muscle palsy. 3. Severe systemic diseases of the heart, liver, or kidneys, as well as psychiatric and mental illness.

     4. Pregnant or breastfeeding patients. 5. Patients who did not undergo gadolinium-enhanced MRI of the cavernous sinus. 6. Patients younger than 18 years at the time of enrollment. 7. Onset of symptoms more than 1 week before admission. 8. Incomplete data or follow-up period less than 6 months. 9. Disagreements in disease diagnosis.

Cavernous sinus idiopathic inflammation and microvascular ischemic OCN palsy patients admitted to Department of Neurology, Beijing Tongren Hospital, Capital Medical University, between January 2020 and April 2024 were consecutively recruited. In-hospital medical chart records were retrospectively collected. The patients underwent gadolinium-enhanced MRIs of the cavernous sinus. Patients with ophthalmoplegia caused by infections, stroke, tumors, injuries, aplasia, carotid cavernous fistulae, aneurysms, and intracranial hypotension were excluded.